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Building Better Drugs from Sugars SUPERSYMMETRY in atomic nuclei ARTIFICIAL HEARTS and the alternatives A NOSE THAT “SEES” Sweet Medicine Sweet Medicine 15 WAYS TO EXPOSE CREATIONIST NONSENSE JULY 2002 $4.95 WWW.SCIAM.COM Infrared Lasers for the Internet’s Last Mile COPYRIGHT 2002 SCIENTIFIC AMERICAN, INC. BIOTECHNOLOGY 40 Sweet Medicines BY THOMAS MAEDER A new generation of drugs will be based on sugars —a neglected set of molecules. INFORMATION TECHNOLOGY 48 Last Mile by Laser BY ANTHONY ACAMPORA Short-range infrared lasers could beam broadband multimedia services into homes and offices. ZOOLOGY 54 The Nose Takes a Starring Role BY KENNETH C. CATANIA The star-nosed mole has what is very likely the world’s fastest and most fantastic nose. MEDICINE 60 The Trials of an Artificial Heart BY STEVE DITLEA A year after doctors began implanting these artificial hearts in patients, the devices’ prospects are uncertain. PHYSICS 70 Uncovering Supersymmetry BY JAN JOLIE An elusive phenomenon of elementary particle physics has come to light in nuclei. EDUCATION 78 15 Answers to Creationist Nonsense BY JOHN RENNIE Opponents of evolution want to tear down real science, but their arguments don’t hold up. contents july 2002 SCIENTIFIC AMERICAN Volume 287 Number 1 features 40 Sugarcoated cell SCIENTIFIC AMERICAN 5 COPYRIGHT 2002 SCIENTIFIC AMERICAN, INC. 8 SCIENTIFIC AMERICAN JULY 2002 departments 10 SA Perspectives Creationism has no place in the classroom. 12 How to Contact Us 12 On the Web 14 Letters 18 50, 100 & 150 Years Ago 19 News Scan ■ Identity theft is rising—and, so far, unstoppable. ■ Doubts on nuclear bunker busters. ■ Psychologists complain about writing prescriptions. ■ Space station cacophony. ■ How the EPA underestimates indoor air pollution. ■ Filters that let big stuff through. ■ By the Numbers: Dwindling supply of science Ph.D.s. ■ Data Points: Recycling works—sometimes. 34 Innovations Big-name researchers are moving to commercialize nanomanufacturing. 36 Staking Claims Gene switches provide a route around existing patents. 38 Profile: Linda A. Detwiler This Department of Agriculture veterinarian watches out for mad cow disease in the U.S. 86 Working Knowledge New breezes for windmills. 88 Voyages The marvels of engineering inside Hoover Dam. 91 Reviews A Brain for All Seasons: How climate influenced human evolution. 88 38 32 SCIENTIFIC AMERICAN Volume 287 Number 1 Scientific American (ISSN 0036-8733), published monthly by Scientific American, Inc., 415 Madison Avenue, New York, N.Y. 10017-1111. Copyright © 2002 by Scientific American, Inc. All rights reserved. No part of this issue may be reproduced by any mechanical, photographic or electronic process, or in the form of a phonographic recording, nor may it be stored in a retrieval system, transmitted or otherwise copied for public or private use without written permission of the publisher. Periodicals postage paid at New York, N.Y., and at additional mailing offices. Canada Post International Publications Mail (Canadian Distribution) Sales Agreement No. 242764. Canadian BN No. 127387652RT; QST No. Q1015332537. Subscription rates: one year $34.97, Canada $49, International $55. Postmaster: Send address changes to Scientific American, Box 3187, Harlan, Iowa 51537. Reprints available: write Reprint Department, Scientific American, Inc., 415 Madison Avenue, New York, N.Y. 10017-1111; (212) 451-8877; fax: (212) 355-0408 or send e-mail to sacust@sciam.com Subscription inquiries: U.S. and Canada (800) 333-1199; other (515) 247-7631. Printed in U.S.A. Cover illustration by Slim Films columns 37 Skeptic BY MICHAEL SHERMER Readers who question evolution. 93 Puzzling Adventures BY DENNIS E. SHASHA Mathematical justice. 94 Anti Gravity BY STEVE MIRSKY When species get specious. 95 Ask the Experts How long can we stay awake? Could a Tyrannosaurus do push-ups? 96 Fuzzy Logic BY ROZ CHAST The USDA ’s Linda A. Detwiler COPYRIGHT 2002 SCIENTIFIC AMERICAN, INC. Preaching to the converted is unrewarding, so why should Scientific American publish an article about the errors of creationism [see page 78]? Surely this mag- azine’s readers don’t need to be convinced. Unfortu- nately, skepticism of evolution is more rampant than might be supposed. A Gallup poll from 1999 and a National Science Board poll from 2000 both revealed that close to half the American public rejects evolu- tion. Inadequate education plays a part in this —con- fidence in evolution grows with schooling —but clear- ly a lot of remedial tutoring is in order: the NSB also determined that only about half the population rec- ognized the statement “The earliest humans lived at the same time as the dinosaurs” as false. With respect to evolution and science education, this year has already had a mixed record. The state legislatures of Mississippi and Georgia considered bills that would have undermined the teaching of evo- lution (thankfully, the bills died in committee). The Cobb County Board of Education in Georgia voted to insert into new science textbooks a notice that evolution is “just one of several theo- ries” about the diversity of life on earth. As of this writ- ing, the Ohio Board of Edu- cation is still deciding whether to give equal time to the cre- ationist ideas known as intelli- gent design. Ideas deserve a fair hearing, but fairness shouldn’t be an ex- cuse for letting rejected, inade- quate ideas persist. Intelligent de- sign and other variants of cre- ationism lack credible support and don’t mesh with the naturalistic fab- ric of all other science. They don’t deserve to be taught as legitimate scientific alternatives to evolution any more than flat-earth cosmology does. Unfortunately, creationism’s allies set up smoke screens. For example, writing in the Washington Times, Senator Rick Santorum of Pennsylvania claimed that the federal education bill signed into law this year con- tained a provision that “where topics are taught that may generate controversy (such as biological evolu- tion), the curriculum should help students to under- stand the full range of scientific views that exist.” But biologist Kenneth R. Miller of Brown University has pointed out that the law says no such thing —the “San- torum amendment” was removed before the bill was signed. Addressing the Ohio education board, two promi- nent advocates of intelligent-design theory, Jonathan Wells and Stephen C. Meyer, submitted a bibliogra- phy of 44 peer-reviewed papers that they said “chal- lenge” evolutionary explanations for life’s origins. Sleuthing by the National Center for Science Educa- tion revealed, however, that this list is less than it seems. The NCSE attempted to contact all the authors of those papers and heard from 26 of them, rep- resenting 34 of the 44 publica- tions. None of those authors agreed that their work contradicted evolu- tion, and most insisted that their work actually supported it (the com- plete story can be found at www. ncseweb.org). Readers of Scientific American are well placed to expose ignorance and combat antiscientific thought. We hope that this article, and a new resource center for defending evolution at www. sciam.com, will assist them in doing so. 10 SCIENTIFIC AMERICAN JULY 2002 MATT COLLINS SA Perspectives THE EDITORS editors@sciam.com Bad Science and False Facts COPYRIGHT 2002 SCIENTIFIC AMERICAN, INC. How to Contact Us EDITORIAL For Letters to the Editors: Letters to the Editors Scientific American 415 Madison Ave. New York, NY 10017-1111 or editors@sciam.com Please include your name and mailing address, and cite the article and the issue in which it appeared. 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Both the space shuttle and the International Space Station are facing severe cutbacks, forcing NASA to reallocate funds from unmanned missions that would probably yield greater scientific returns. Can the agency that took us to the moon get back on track? Secrets of the Stradivarius With a tone that is at once brilliant and sonorous, the violins created by Antonio Stradivari in the 17th and 18th centuries stand alone. For years, instrument makers and scientists have studied the extraordinary violins, hoping to uncover their secrets. Now one investigator believes that reproduction of that legendary sound is within reach. The key, expounds Joseph Nagyvary of Texas A&M University in an interview with Scientific American, lies in the chemistry. ASK THE EXPERTS What is synesthesia? Thomas J. Palmeri, Randolph B. Blake and René Marois of Vanderbilt University explain. www.sciam.com/askexpert/ TECHNOLOGY AND BUSINESS CHANNEL www.sciam.com/techbiz/ Get the full picture of how technology is changing the way companies conduct business. Log on to the NEW TechBiz channel at ScientificAmerican.com PLUS: DAILY NEWS ■ DAILY TRIVIA ■ WEEKLY POLLS COPYRIGHT 2002 SCIENTIFIC AMERICAN, INC. MORE REFLECTIONS ON READING “How Should Reading Be Taught?” gives information about a problem that has been solved in many schools. As an ele- mentary school principal, I work with teachers to be sure we teach reading in ways that blend the necessary mastery of phonics (word study) with the enjoyment of literature. Several current approaches, widely used for at least 10 years, combine phonics with literature. For example, one of the “blocks” in the “four blocks” ap- proach is the study of phonics. The oth- er blocks are guided reading, indepen- dent reading, and writing. A second approach, “guided read- ing,” developed out of the Reading Re- covery program at Ohio State University, includes phonics. The teacher frequently assesses each child and teaches the student using eight- to 10-page single-story books selected to be at precisely the student’s current reading level. This article too nar- rowly refers to guided reading as a whole- language approach that neglects phonics. JANE J. SHARP Finley Road Elementary School Rock Hill, S.C. I thought your article was very well re- searched and was a true representation of the many experiences I have had in teach- ers college classes and in my work as both a student teacher and teacher. My read- ing professors did not teach us how to provide direct instruction in phonics; they sincerely believed that linguistic concepts would be “absorbed” by the students as they were exposed to a “literature-rich” classroom experience. Fortunately, we are entering an era in which it is recognized that a balance between the two philoso- phies is necessary as well as possible. ELAINE R. MALONE Lincoln, Neb. WORLDWIDE-COMPUTER WOES The idea of a superfast global operating system wherein some unknown person’s file fragments are stored on my comput- er is wonderful [“The Worldwide Com- puter,” by David P. Anderson and John Kubiatowicz]. But as America drowns in litigation and the definition of a “right” becomes ever more clouded, the prevail- ing impetus is to build walls around my computer, not tear them down. JOSH LACEY Los Angeles The authors failed to address the band- width needs of such a global network. Al- though installation of high-bandwidth residential service is growing exponen- tially, most providers anticipate —and base their pricing structure on —idle bandwidth time, which the authors’ sys- tem would use. This is why my residen- tial DSL service costs $40 a month, whereas commercial service, with com- parable bandwidth, runs about 10 times that amount. A closed-network environment, in which bandwidth and hardware are more 14 SCIENTIFIC AMERICAN JULY 2002 A FAVORITE TOPIC of many letter writers for the March issue was reading —specifically, “How Should Reading Be Taught?” by Keith Rayner, Barbara R. Foorman, Charles A. Perfetti, David Pe- setsky and Mark S. Seidenberg. One flaw with phonetics as a teaching tool, pointed out George Chudolij of Massachusetts, is that “unfortunately, the English language is not 100 percent phonetic, which contributes to confusion. I say revamp the writ- ten spelling of the language and eliminate unnecessary letters. Thus, there would not be any ‘x’s or ‘c’s. The ‘a’ as in ‘father’ would remain the same; ‘a’ as in ‘fat’ would be written with an umlaut, as German does today for this very purpose. ‘Enough’ would be ‘enuf,’ and so on.” Sumthing tu pander äs yu reed tha leters an tha nekst tu payjez. EDITOR IN CHIEF: John Rennie EXECUTIVE EDITOR: Mariette DiChristina MANAGING EDITOR: Michelle Press ASSISTANT MANAGING EDITOR: Ricki L. Rusting NEWS EDITOR: Philip M. Yam SPECIAL PROJECTS EDITOR: Gary Stix SENIOR WRITER: W. Wayt Gibbs EDITORS: Mark Alpert, Steven Ashley, Graham P. Collins, Carol Ezzell, Steve Mirsky, George Musser CONTRIBUTING EDITORS: Mark Fischetti, Marguerite Holloway, Michael Shermer, Sarah Simpson, Paul Wallich EDITORIAL DIRECTOR, ONLINE: Kristin Leutwyler SENIOR EDITOR, ONLINE: Kate Wong ASSOCIATE EDITOR, ONLINE: Sarah Graham WEB DESIGN MANAGER: Ryan Reid ART DIRECTOR: Edward Bell SENIOR ASSOCIATE ART DIRECTOR: Jana Brenning ASSISTANT ART DIRECTORS: Johnny Johnson, Mark Clemens PHOTOGRAPHY EDITOR: Bridget Gerety PRODUCTION EDITOR: Richard Hunt COPY DIRECTOR: Maria-Christina Keller COPY CHIEF: Molly K. Frances COPY AND RESEARCH: Daniel C. 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Lux DIRECTOR, ANCILLARY PRODUCTS: Diane McGarvey PERMISSIONS MANAGER: Linda Hertz MANAGER OF CUSTOM PUBLISHING: Jeremy A. Abbate CHAIRMAN EMERITUS: John J. Hanley CHAIRMAN: Rolf Grisebach PRESIDENT AND CHIEF EXECUTIVE OFFICER: Gretchen G. Teichgraeber VICE PRESIDENT AND MANAGING DIRECTOR, INTERNATIONAL: Charles McCullagh VICE PRESIDENT: Frances Newburg Established 1845 ® Letters EDITORS@ SCIAM.COM COPYRIGHT 2002 SCIENTIFIC AMERICAN, INC. easily managed, is where technology holds enormous promise. Imagine harnessing (and selling) the power of an entire uni- versity or corporate campus. Such a set- ting would be the perfect incubator for the quantity and quality of applications need- ed to take advantage of this technology. ANDY JELAGIN Network Administrator Kaleidoscope Imaging/Brandscope Design Chicago GENOME RIGHTS I read with interest Gary Stix’s ac- count of a mock patent dispute over the DNA of the fictional Salvador Dolly [Staking Claims]. As a pro- fessional sculptor, I was immediate- ly struck that Dolly’s attorneys failed to approach the case from the correct basis: this is clearly not an is- sue of patent law but of copyright law. A person’s genome is nothing more than a unique expression of information. And expression, whether it is artistic or genetic, is protected by copyright. As the sole originator and hold- er of his genome, Dolly can demand payment for every copy or “excerpt” made by a company. With poly- merase chain reaction, or PCR, repli- cation, that could amount to quite a sum. These royalties would be pay- able, under current law, for 70 years beyond Dolly’s death. CHRISTOPHER PARDELL Fallbrook, Calif. ABUSE AND HEALING As a clinical social worker who treats adult survivors of child abuse, I was grateful for your article and the author’s years of research on the effects of child- hood trauma on the brain [“Scars That Won’t Heal: The Neurobiology of Child Abuse,” by Martin H. Teicher]. I must, however, take strong exception to the ti- tle and to repeated statements that this research shows that the “developing mind may never truly heal” and that the dam- age is “irrevocable” or “hardwired.” There are no data reported to say that such harm to the brain is irreversible. In- deed, the analogy of “software” and “hardware” is especially flawed, because the brain is an evolving organ; new cells, new connections, changes in its chemistry continue into old age. For example, many people have been able to recover full function after stroke destroyed critical ar- eas of their brain. Studies have shown that brain-function changes after thera- py for depression are similar whether the treatment is medication or talk therapy. Psychotherapists such as myself see most of our clients gain dramatic and meaningful reductions in the problemat- ic symptoms and behaviors caused by childhood abuse. Although full recovery may take years, it is irresponsible to take away this hope based on an absence of data. MICHELLE SALOIS University City, Mo. TEICHER REPLIES: I celebrate your spirit of hope, but I stand by what I’ve written. Through therapy, individuals can adapt to and com- pensate for these experiences. But there is no evidence to suggest that structural (as op- posed to functional) alterations in the brain are reversible through therapy. Studies on the effects of antidepressant medications and psychotherapy show alterations in metabo- lism and blood flow but do not show any changes in gross anatomy. It is most unlike- ly that an adult with 40 percent reductions in the size of his or her corpus callosum could have this region regrow through any known form of treatment. Individuals often re- cover function after stroke, to use your example, through compensatory pro- cesses, but the destroyed regions re- main destroyed. I have in fact examined brain function in individuals with a his- tory of childhood maltreatment who, through therapy, have made an appar- ent full clinical recovery, but their brains functioned quite differently than normal in the recall of neutral versus disturbing memories. As you’ve indicated, patients can re- spond dramatically to certain forms of therapy, although other sequelae, such as borderline personality disorder, can be much more intractable. I have not re- ceived a single letter from a patient indi- cating that this article caused him or her to lose hope; I have received many letters from individuals thanking me for helping to explain why their condition has en- dured so long despite therapy. The best hope for adaptation or functional recovery is with early intervention when the brain is more plastic. There is, however, a pressing need for better treatments and a crucial need for the prevention of childhood abuse. BOUNCING BABY UNIVERSES “Been There, Done That,” by George Musser [News Scan], suggests that instead of a singular universe started by a big bang, we live in one of two parallel uni- verses that repeatedly bounce off each oth- er like a ball connected to a paddle by a rubber band. Fascinating idea, but it needs a catchy name. How about the Big Boing? STAN BENJAMIN Garrett Park, Md. 16 SCIENTIFIC AMERICAN JULY 2002 STUART BRADFORD Letters EARLY ABUSE, research shows, leads to indelible changes in a youngster’s developing brain. COPYRIGHT 2002 SCIENTIFIC AMERICAN, INC. JULY 1952 RED SCARE—“U.S. scientists have been running into trouble getting permission to travel abroad. The most recent publicized case being that of Linus Pauling, head of the Department of Chemistry and Chem- ical Engineering at the California Institute of Technology. Pauling had planned to at- tend a conference of the Royal Society of London on protein structure. He said a State Department official told him that the decision had been made ‘because of suspi- cion that I was a Communist and because my anti-Communist statements had not been sufficiently strong.’ Pauling had de- clared that he was not a Communist and had pointed out that his resonance theo- ry of chemical combination had been at- tacked in the Soviet Union. He has reap- plied for a passport and sent a letter to President Truman.” JULY 1902 THE LONGEST BRIDGE — “The last of the strands has now been completed on the four great cables which will support the massive roadway of the new East River Bridge between Brooklyn and Manhattan [see illustration]. Each cable is 2,985 feet in length from an- chorage to anchorage. The hor- izontal distance from saddle to saddle across the main span is 1,600 feet. The cables have an average breaking strength of 225,000 pounds per square inch; a truly marvelous result, and one which places these ca- bles far ahead in point of tensile strength of any other structural material yet used in bridge building.” [Editors’ note: The Williamsburg Bridge, which opened on December 19, 1903, was the longest suspension bridge in the world until 1924.] RADIO ASTRONOMY—“M. Charles Nordmann [sic] gives an ac- count of experiments at the Mont Blanc observatory to determine whether waves of an electro-magnetic nature are given off by the sun. He used a horizontal mast wire 550 feet long which was laid along the Bossons glacier upon wood insulating supports so that the sun’s rays would fall directly upon it. Nordmann used a coher- er which was placed in a vessel of mercury. The experiment was repeated several times on the 19th of September during fine weather, but no deflection of the gal- vanometer could be obtained. This seems to prove that the sun does not emit such electro-magnetic waves, or in the contrary case such waves are absorbed by the sun’s or earth’s atmosphere.” [Editors’ note: Successful experiments by Karl Jansky in 1931 are considered the beginning of ra- dio astronomy.] THE END OF SCIENCE — “President Minot, of the American Association for the Ad- vancement of Science, stated that con- sciousness is at once the oldest problem of philosophy and the youngest problem of science. Consciousness ought to be re- garded as a biological phenomenon, which the biologist has to investigate in order to increase the data concerning it. The biol- ogist can often tell why a given function is performed, but how the function exists he can tell very imperfectly. It is more im- portant to seek additional positive knowl- edge than to hunt for ultimate interpre- tations. Correct, intelligent, exhaustive observation is our goal. When we reach it, human science will be complete.” JULY 1852 THE SEWING REVOLUTION—“In 1847 there was not a solitary machine of the sewing machine kind in active operation, in our whole country, if in the world. There are now, we believe, about five hundred. We expect them to create a so- cial revolution, for a good housewife will sew a fine shirt, by one of these little ma- chines, in a single hour. The time thus saved to wives, tailors, and seamstresses is of incalculable importance. Young ladies will have more time to devote to orna- mental work (it would be better for them all if they did more of it). We suppose that, in a few years, we shall all be wearing shirts, coats, trousers, boots, and shoes — the whole habiliments of the genus Homo —stitched and com- pleted by the Sewing Machine.” MARKED FISH—“The Scotch commissaries of fisheries have been adopting an ingenious de- vice for learning the migrations of the salmon. They have marked a large number of fish, hatched from spawn, deposited last year in the river Tweed, by placing around them a belt or ring of india rubber numbered and dat- ed. All fishermen, taking such marked fish, are desired to take note of the weight, the place and date of capture, and vari- ous other particulars named in the directions. The idea is a nov- el and amusing one.” 18 SCIENTIFIC AMERICAN JULY 2002 Subversion Suspicion ■ Consciousness Data ■ Social Revolution BUILDING the world’s longest suspension bridge, 1902 50, 100 & 150 Years Ago FROM SCIENTIFIC AMERICAN COPYRIGHT 2002 SCIENTIFIC AMERICAN, INC. www.sciam.com SCIENTIFIC AMERICAN 19 E very year scam artists reportedly cre- ate some 700,000 false identities — enough to fill a virtual San Francisco. That estimate is conservative, insists Norman A. Willox, Jr., of the National Fraud Center, a consulting firm. It’s based on the number of fake credit cards, bank accounts, driver’s li- censes and other supposed proofs of identity that are being uncovered. Data from the U.S. General Accounting Office suggest that iden- tity fraud has been increasing by roughly 50 percent a year since 1999. And despite corpo- rate and government moves toward universal IDs, the quest for absolute proof that you are who you say you are appears quixotic. Creating a false identity is easy, especial- ly if you start with a real one. A few visits to Web-based public directories (or local li- braries and records offices) can yield address- es and phone numbers past and present, date of birth, employers, mother’s maiden name and similar vital personal data. Add an ille- gitimately obtained Social Security or credit- card number, and an impostor has almost as solid a case for claiming to be someone as the real person does. Criminal information bro- kers even package up complete identities for sale, according to Willox. In a society in which people regularly do business without meeting face to face, a sys- tem that bases trust on a few dozen bytes of lightly guarded data is fundamentally inse- cure. Federal estimates of losses from identity fraud are well up in the billions of dollars a year, and those whose names or numbers are used as a basis for fake identities may spend several years and thousands of dollars trying to clear their records. Some have even been arrested and imprisoned for crimes committed by their doppelgängers. The rapid expansion of glob- al trade, Willox says, is at risk. The rise in identity theft, coupled with the current climate of fear about terrorism, has led organizations ranging from database builder Oracle to the American Association of Motor Vehicle Administrators to propose the development of tamperproof IDs that would positively verify everyone’s identity for purposes as diverse as opening a bank ac- count or getting on an airplane. Besides the usual name, address, birth date and ID num- ber, proposed computer-readable identity cards could also contain biometric data such as fingerprints or iris scans to make falsifica- tion impossible —assuming that it was issued to the right person in the first place. But in addition to the obvious civil-liber- ties implications of an ID that could be used to track every commercial or government trans- INFOTECH Who’s Who CAN DIGITAL TECHNOLOGY REALLY PREVENT IDENTITY THEFT? BY PAUL WALLICH SCAN news New “knowledge-based” techniques may be a means for better identity verification. Putting our surveillance society to good use, these algorithms match purported identifying information against dozens of databases, including some to which a scammer would, it is hoped, have no access. An impostor might be able to match a few items in a legitimate dossier but not the entire file. This knowledge- based approach can be more than 99.9 percent accurate. Still, there will always be a need for manual overrides in case the information about a real person doesn’t match what’s in the databases. Studies have shown, for example, that 30 percent of credit reports contain significant errors. AUTHENTICITY VIA DATABASES FAKE IDs are not always so easy to spot. COPYRIGHT 2002 SCIENTIFIC AMERICAN, INC. 22 SCIENTIFIC AMERICAN JULY 2002 U.S. DEPARTMENT OF ENERGY news SCAN In only about 20 percent of cases is the method of identity theft known. Of those, the most common are: Relationship through victim: 52.5% Stolen or lost wallet/purse: 34.4% Mail theft/false address change filed: 13.4% Compromised records: 6.9% Burglary: 3.6% Internet solicitation/purchase: 2.4% SOURCE: General Accounting Office, March 2002. Total exceeds 100 percent because some victims reported that multiple methods were used. FAST FACTS: STEALING A LIFE A joint report of the U.S. Departments of Defense and Energy estimates that more than 10,000 potential hardened and deeply buried targets worldwide contain cru- cial infrastructure and possibly chemical or bi- ological weapons. Although many of these tar- gets are vulnerable to conventional weapons, hundreds are fortified below 25 to 100 meters of concrete. Nuclear weapons are the only sure means to defeat these strongholds, some defense analysts say, calling for a new gener- ation of weapon: a low- yield, earth-penetrating warhead that would de- liver a knockout blast without releasing plumes of deadly radioactivity. But such weapons, vari- ous physicists argue, are not technically feasible. “Earth-penetrating weapons cannot pene- trate deeply enough to contain the nuclear explosion and will neces- sarily produce an especially intense and dead- ly radioactive fallout,” concludes Robert W. Nelson of the Program on Science and Global Security at Princeton University. In a paper to appear this summer in the journal Science and Global Security, Nelson calculates that a one- kiloton, earth-penetrating “mini nuke” used in an urban environment such as Baghdad would spread a lethal dose of radioactive fall- out over several square kilometers and result in tens of thousands of civilian fatalities. Regard- less of its impact velocity or its construction material, no missile can penetrate reinforced concrete more than about four times its length, Nelson calculates, a number supported by data he received from Sandia National Labo- ratories via the Freedom of Information Act. Penetration through rock or soil is more variable —and more controversial. Gregory H. Canavan, a senior scientist at Los Alamos National Laboratory, believes that Nelson’s equations show that depth-to-length penetra- tion of 30 is possible in dirt; Nelson denies action, an ostensibly perfect token of identity could reduce security rather than enhance it. One problem, says Lauren Weinstein, mod- erator of the Internet-based Privacy Forum, is that you shouldn’t confuse proof of identity with proof of trustworthiness. The FBI and CIA knew exactly who Robert Hanssen and Aldrich Ames were, for example, but that did- n’t help stop their espionage. Similarly, Wein- stein argues, relying on a “frequent traveler card” for airline security could lead to relaxed vigilance just when it’s most needed. Tamperproof ID would be a “high-value target,” Weinstein explains. Given how often criminals dupe or suborn the officials who is- sue birth certificates or driver’s licenses (and how many false identities are already in place), even 99.9 percent accuracy would give thou- sands of fake people a government impri- matur. Biometric certification of dubious iden- tities could make life even worse for victims of identity fraud —today as a last resort you can cancel all your accounts and even get a new So- cial Security number, “but how do you cancel your fingerprints?” Weinstein points out. Bruce Schneier of Counterpane Internet Security in Cupertino, Calif., suggests that in- stead of spending more resources on a holy grail of perfect identification, governments and businesses should accept that ID failures will occur and make reporting identity fraud as easy as reporting a single lost or stolen cred- it card. “Give the liability to the person who can fix the problem,” Schneier says, noting that consumers rather than information ven- dors now bear the costs of correcting the dam- age done when ID data are stolen or falsified. In such a regime, more limited forms of iden- tification —each suited to a small range of transactions —might turn out to be more cost- effective and secure than a single overarching digital persona. Ground below Zero ARE BUNKER-BUSTING NUCLEAR WARHEADS A VIABLE OPTION? BY DAVID APPELL WEAPONS NUCLEAR BLAST for underground bunkers would be much smaller than this 1962 detonation of 104 kilotons at 195 meters deep, but critics say a similar “Roman candle” effect would occur. COPYRIGHT 2002 SCIENTIFIC AMERICAN, INC. [...]... yield a new generation of drug therapies RANDI BEREZ By Thomas Maeder 40 SCIENTIFIC AMERICAN JULY 2002 COPYRIGHT 2002 SCIENTIFIC AMERICAN, INC COPYRIGHT 2002 SCIENTIFIC AMERICAN, INC Now that the human genome has been deciphered, much of the fanfare surrounding it has transferred to the proteome, the full complement of proteins made from the genetic “blueprints” stored in our cells Proteins, after all,... Consortium for Functional Genomics: http://glycomics.scripps.edu www.sciam.com SCIENTIFIC AMERICAN COPYRIGHT 2002 SCIENTIFIC AMERICAN, INC 47 AS BUSINESSES adopt free-space optics technology, nearby residents could get affordable access to broadband multimedia services COPYRIGHT 2002 SCIENTIFIC AMERICAN, INC Last Mile Short-range infrared lasers could beam advanced broadband multimedia services directly... College”; By the Num- crease the participation of non-Hispanic bers, October 1999] White women and mi- white men would yield somewhat smaller renorities have been increasingly attracted to turns: if they got Ph.D.s at the same rate as in S&E doctoral programs, as have African- 1980, about 1,700 to 1,800 would be added and Hispanic-Americans, but these two mi- annually nority groups, unlike Asian-Americans,... Depending on weather conditions, FSO links can extend from a few city blocks to one kilometer— far enough, though, to get broadband traffic from the backbone to many end users and back Because bad weather—thick fog, mainly—can severely curtail the reach of these www.sciam.com SCIENTIFIC AMERICAN COPYRIGHT 2002 SCIENTIFIC AMERICAN, INC 49 line-of-sight devices, each optical transceiver node, or link... After being emitted by the 85 0- or Applications for Free-Space Optics Last-mile access: High-speed data links that connect business and consumer end users with Internet service providers and other metropolitan-area and wide-area fiber networks ■ Cellular backhaul: The means to carry cell-phone traffic from local antenna towers back to facilities wired into the public switched-telephone network ■ Enterprise... to keep the transmitter and receiver on target JULY 2002 COPYRIGHT 2002 SCIENTIFIC AMERICAN, INC Spanning the Connectivity Gap EXTENDING BROADBAND THE LAST MILE With the multitransceiver free-space optical node (below) installed on buildings (at right), a mesh network of short-range, two-way laser links can extend the distribution of broadband data from served cities out to towns, neighborhoods and... Overview /Sugars Sugars modify many proteins and fats on cell surfaces and participate in such biological processes as immunity and cell-to-cell communication They also play a part in a range of diseases, from viral infections to cancer ■ Scientists are finally overcoming the obstacles impeding efforts to decipher the structures of complex sugars and to synthesize sugars for use in research and as drugs. .. cells that line blood vessel walls Anti-inflammatory drugs under study aim to prevent the white cells from binding to selectins ( b) Endoplasmic reticulum a White blood cell Sugar Endothelial cell b Red blood cell Selectin blocker Selectin Activated white cell causing inflammation COPYRIGHT 2002 SCIENTIFIC AMERICAN, INC Cell prevented from causing inflammation Sugar-Taming Technologies Technical breakthroughs... when the common euphemism for the site of the worst terrorist attack on U.S soil is borrowed from Hiroshima, Americans might want to think carefully about the feasibility of a nuclear attack without nuclear consequences David Appell is based in Gilford, N.H SCIENTIFIC AMERICAN JULY 2002 COPYRIGHT 2002 SCIENTIFIC AMERICAN, INC ADAM BUTLER AP Photo news PSYCHOLOGY news SCAN Inner Turmoil PRESCRIPTION PRIVILEGES... the Amgen and the Genzyme cases have been appealed But no matter what the outcome, the gene-switch companies are proving that however dense the intellectual-property thicket becomes, someone will find a way to crawl through it if the incentives are sufficient SCIENTIFIC AMERICAN JULY 2002 COPYRIGHT 2002 SCIENTIFIC AMERICAN, INC JOHN M C FAUL Molecular switches provide a route around existing gene patents . 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